On my dads 2001 Park Avenue the SERVICE STABILITY SYSTEM message will show up on the DIC while driving down the road. The dealer said it was because the rear shocks were leaking (which makes no sense if you ask me) so he replaced the shocks (which by the way be advised GM'* revised Delco shocks wont work on the cars they are designed for particularly the park avenue and bonneville) but the error is still appearing on the dic. The dealer then said they have to clear the code from the system (Which they charge $50) or he said to just live with it for a while and the system will reset on its own. Is this person full of crap or is there something else we should look at?

I suppose it would be possible that if the shocks were bad enough that the tires would often lose contact with the road, the system could get erratic readings from the wheel speed sensors setting that code.

If they did the work with the new shocks, they should have cleared the code themselves at the time...not charge extra to do it later. Most codes will go away after a certain number of tests without a failure. I don't know for sure on that one, but I would think it should shut off fairly quickly.

The most common cause for that warning on the Bonnevilles has been the steering position sensor, followed by a bad wheel speed sensor. So far, no reports on bad shocks causing the problem.

These Dealers are something else!
I have the same message on my a DIC for over a year and so do many others , it hasnt caused any issues so far except for the DIC annoyance.